Depending on the time of day, or the number of people using the same Internet service provider as you simultaneously, the quality of your Internet connection can vary. Here are some things you can check:

Close extra browser windows, tabs, and applications.
Having too many program windows, Web browser tabs, or applications open at one time can slow your system down.

Make sure you have a strong Internet connection.
Check your Internet connection speed. You can find free "Internet speed test" Websites in Yahoo Search. If you have frequent problems with connection speed, contact your Internet service provider.